In addition to the advice mentioned here, it will also help attendance if you advertise it on meetup.com.
Our Chicago meetup group also has a google group for announcing meetups, discussing venues, etc. That way, some people who may be interested in Chicago meetups but who may forget to check LW (or not check at the right time) can also receive notice.
No. I could probably write one, but there isn't much to it. Decide that your city/region has rationalists likely to come to a Less Wrong meetup. Pick a date. Pick a venue (coffee shop, bar/restaurant, home/apartment, all are fine, as long as it won't be too loud for serious conversation). Post on Less Wrong main page. Everyone shows up and talks in unorganized fashion. You can pick a topic ahead of time if you want, but it's not necessarily or even strictly preferred.
I think it would be quite useful. You, Alicorn, and Jasen (off the top of my head) know a lot more than you realize about doing this. If you created a common sense guide for this with some tips on how to schedule, how to find people, and how things have run in your experience, you could really lower the barriers to new meetups forming.
I'm planning to encourage SIAI volunteers to start these groups in new areas and it would be helpful to be able to link them to a guide that explains what I want them to actually be doing since "Start a Less Wrong Meetup" is a pretty opaque request if you've never been to one yourself (a position most new organizers will find themselves in).
You, Alicorn, and Jasen (off the top of my head) know a lot more than you realize about doing this.
The thing is, they have to realize that they know it in order to write a good guide to it. A lot of making meetups happen is caring enough to ensure they happen and putting in the effort to contact other people and take charge- and that's not really something you can learn from a guide.
how to schedule, how to find people
I was already aware of some people in my area (SarahC and Tom McCabe, plus thomblake who already lives where I do). I got all of 'em to agree on a day (via IM), declared the start time to be noon, had food ready then, sat around for an hour because everyone was late, and proceeded to participate in idle chit-chat until my guests departed.
It seems to work a lot better if there's one determined person in charge of organizing it.
Just pick some reasonable date (like "two weeks from now" kind of reasonable, short notice work but is problematic), some quiet easy to reach venue, and announce it loudly together with your contact details.
It probably helps with coordination to announce it as something that will happen, not as something that might happen depending on interest.
If you're meeting in a public place, definitely have some paperclips or other obvious sign with you, so you're easily found by people who've never seen you.
(Someone should possibly ask Art Lebedev Studios for kind permission regarding said paperclip at some stage ... I say "kind permission" because it's not like LW is rolling in cash.)
n/t